- try to preserve a bit more information about incorrect use of user variables to print more meaningful error messages. This is not complete yet and will need integration with the previous commit.

src/p_actionfunctions.cpp

@@ -78,6 +78,7 @@
 #include "p_spec.h"
 #include "templates.h"
 #include "vm.h"
+#include "v_text.h"
 #include "thingdef.h"
 #include "math/cmath.h"
 
@@ -132,6 +133,15 @@ bool ACustomInventory::CallStateChain (AActor *actor, FState *state)
 
 		if (state->ActionFunc != NULL)
 		{
+			if (state->ActionFunc->Unsafe)
+			{
+				// If an unsafe function (i.e. one that accesses user variables) is being detected, print a warning once and remove the bogus function. We may not call it because that would inevitably crash.
+				auto owner = FState::StaticFindStateOwner(state);
+				Printf(TEXTCOLOR_RED "Unsafe state call in state %s.%d to %s which accesses user variables. The action function has been removed from this state\n",
+					owner->TypeName.GetChars(), state - owner->OwnedStates, static_cast<VMScriptFunction *>(state->ActionFunc)->PrintableName.GetChars());
+				state->ActionFunc = nullptr;
+			}
+
 			VMFrameStack stack;
 			PPrototype *proto = state->ActionFunc->Proto;
 			VMReturn *wantret;